Some Caterpillar Workers Cross Picket Line

JOLIET, Ill.—After nearly three months, a strike by Caterpillar Inc. workers here has become a war of attrition as the number of union members crossing the picket line gradually rises.

Caterpillar, a global maker of construction and mining equipment, said 95 of the International Association of Machinists and Aerospace Workers members had returned, out of 780 or so workers represented by the IAM. The union said Tuesday it had confirmed that 79 had gone back to work. A union official said the IAM bases its number on...